The top set isn't x chained from what I can see. Personally, I would have x chained the whole stack. Sometimes I'll even build a bulkhead too for something like that as a little extra.
10' wide is not to bad, we are constantly doing 11 and 12' loads. After a while you will get comfortable with them and not notice the width.
I remember my first, a CAT 325. I felt like a bobblehead checking the mirrors constantly to make sure I wasn’t crowding anybody. I knew federal freeway standards dictate lanes to be 12’ wide, so that was a slight encouragement.
Like your story, currently pulling ny first open deck load, it's a different ballgame than slamming doors. Its like you said, feel like a complete newbie.